The present invention relates to rotating electrical machines (e.g. electrical motors and generators) and in particular to a rotating electrical machine employing variable capacitance with a capacitor plate supported on fluid bearings.
Electrical motors and generators share similar structures of an electrically interacting stator and rotor and may be collectively termed “rotating electrical machines.” Conventional rotating electrical machines may be roughly characterized as exploiting magnetic fields and/or change in inductance (reluctance) between moving parts. It is also possible to construct rotating electrical machines that exploit electric fields and/or change in capacitance between the moving parts. Such varying capacitance rotating electrical machines have a number of advantages over conventional varying inductance motors including the elimination of magnets, ferrous materials, and high current copper windings. As a result, such varying capacitance rotating electrical machines allow potentially higher-speed operation (by eliminating the mass of ferrous materials and magnets and the complex structure of windings) and higher temperature operation (as limited by magnetic materials and winding insulation), and higher efficiency by operating at high voltages with low resistive losses.
An obstacle to the development of varying capacitance rotating electrical machines is the relatively low capacitive coupling that can be obtained between the stator and rotor resulting in low power density (e.g. the need for physically large devices for a given power level).